It is against regulations to connect a non issued computer to the DoD (USNA) network. Most Mids go into DTA and connect at one of the various wireless cafe's.
Sponsor Families: you will get information in the Permit to Report package about the Sponsor Family program. It will be your choice if you want to participate. Not all Mids have sponsors - some by choice and others by unforeseen circumstances.
You will get a questionnaire to fill out and then over Plebe Summer the Academy will match you with a family. You should meet your Sponsor family toward the end of Plebe Summer. There is an afternoon that the Sponsors come to Alumni Hall to meet their new sponsor kids. Many sponsors will also have other Mids so you can end up with sponsor brothers and sisters in other classes or even in the Class of 2013. Sometimes it does happen that a Sponsor family will not make the event.
Some relationships will work out very well. Others will not. Some Mids will spend a lot of time with their Sponsor Family, others will not. Some sponsor Moms and Dads will help with transportation to the Airport, provide a place to crash for overnights and have their sponsor Mids bring friends.
Sometimes when the relationship does not work you can get "adopted" by a friends family.
Although this is a link that is intended for the Sponsor - you may learn some things from the FAQ's
http://www.usna.edu/Sponsor/faq.htm